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Help! Cracked BB shell lug!

Started by Scott Gordo · · Last activity · 32 posts · 759 views

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Cycling Equipment
Published
8 September 2007
Last activity
12 September 2007
Original author
Scott Gordo
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32
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  1. I've discovered a massive crack in the bottom bracket lug of my
    Reynolds 531 1975 Paramount track frame that runs along the entire
    circumference at the base of the lug's seat tube opening.

    To clarify, the crack is in the lug, not the seat tube, The lugs are
    Nervex, but I think I remember reading that they used a different bb
    lug, The crack runs along the bb shell, around the back, back across
    the bb shell, and traces its way over the top of the down tube opening
    to meet at the other side.

    What a freakin' bummer!

    Fixable? Recommendations? Welding in place would be cheap and I know a
    guy but it sounds too hot, I don't know any brazers, maybe I need a
    new lug installed? I'm not concerned about paint or anything, as this
    isn't a show bike and it has already been crappily repainted. I just
    don't want to *sniff* give her up.

    Gah!

    TIA.

    Scott

  2. Scott Gordo said:

    I've discovered a massive crack in the bottom bracket lug of my
    Reynolds 531 1975 Paramount track frame that runs along the entire
    circumference at the base of the lug's seat tube opening.

    To clarify, the crack is in the lug, not the seat tube, The lugs are
    Nervex, but I think I remember reading that they used a different bb
    lug, The crack runs along the bb shell, around the back, back across
    the bb shell, and traces its way over the top of the down tube opening
    to meet at the other side.

    What a freakin' bummer!

    Fixable? Recommendations? Welding in place would be cheap and I know a
    guy but it sounds too hot, I don't know any brazers, maybe I need a
    new lug installed? I'm not concerned about paint or anything, as this
    isn't a show bike and it has already been crappily repainted. I just
    don't want to *sniff* give her up.

    Gah!

    TIA.

    Scott

    you must be mistaken - r.b.t "engineers" say steel never fatigues!

    seriously though, re-welding the crack is never more than a temporary
    fix - you can never clean the metal interface sufficiently to get a bond
    that removes the stress riser. the only viable repair is shell
    replacement, and frankly, economics of that are questionable if you take
    a decent repaint into account.

    sentimental attachment aside, just look at a replacement frame. my
    bianchi pista is dead straight, rides great, and it's dead cheap. you
    can pick them up on craigslist even cheaper.

  3. That being a classic frame, you ought to contact Waterford Cycles. The
    folks that built the Paramounts in the 70s all went there.

    It wouldn't be cheap, but they'd be more than happy to restore it.

    Scott Gordo said:

    I've discovered a massive crack in the bottom bracket lug of my
    Reynolds 531 1975 Paramount track frame that runs along the entire
    circumference at the base of the lug's seat tube opening.

    To clarify, the crack is in the lug, not the seat tube, The lugs are
    Nervex, but I think I remember reading that they used a different bb
    lug, The crack runs along the bb shell, around the back, back across
    the bb shell, and traces its way over the top of the down tube opening
    to meet at the other side.

    What a freakin' bummer!

    Fixable? Recommendations? Welding in place would be cheap and I know a
    guy but it sounds too hot, I don't know any brazers, maybe I need a
    new lug installed? I'm not concerned about paint or anything, as this
    isn't a show bike and it has already been crappily repainted. I just
    don't want to *sniff* give her up.

    Gah!

    TIA.

    Scott

  4. Scott Gordo said:

    I've discovered a massive crack in the bottom bracket lug of my
    Reynolds 531 1975 Paramount track frame that runs along the entire
    circumference at the base of the lug's seat tube opening.

    To clarify, the crack is in the lug, not the seat tube, The lugs are
    Nervex, but I think I remember reading that they used a different bb
    lug, The crack runs along the bb shell, around the back, back across
    the bb shell, and traces its way over the top of the down tube opening
    to meet at the other side.

    What a freakin' bummer!

    Fixable? Recommendations? Welding in place would be cheap and I know a
    guy but it sounds too hot, I don't know any brazers, maybe I need a
    new lug installed? I'm not concerned about paint or anything, as this
    isn't a show bike and it has already been crappily repainted. I just
    don't want to *sniff* give her up.

    Do not weld over a silver braze. Bad things will happen, really.

    Contact a Waterford dealer (like us!) about a repair/respray, especially
    if you are the original owner. Waterford has original decal sets for
    Paramount owners.

    Yes, IIRC most Kenosha Paramounts have a pressed (RFG?) shell with
    Nervex 3-piece lug set.
    --
    Andrew Muzi
    www.yellowjersey.org
    Open every day since 1 April, 1971

  5. "jim beam" <[email hidden]> wrote in message
    news:[email hidden]...

    Quoted message said:

    you must be mistaken - r.b.t "engineers" say steel never fatigues!

    [censored] again.

    Quoted message said:


    seriously though, re-welding the crack is never more than a temporary
    fix - you can never clean the metal interface sufficiently to get a bond
    that removes the stress riser.

    Spoken like a true poseur - welders usually clean the parts before
    re-welding them. Ever been in a workshop? Thought not.

    Quoted message said:

    the only viable repair is shell replacement, and frankly, economics of
    that are questionable if you take a decent repaint into account.

    [censored].

    Quoted message said:

    sentimental attachment aside, just look at a replacement frame. my
    bianchi pista is dead straight, rides great, and it's dead cheap. you can
    pick them up on craigslist even cheaper.

  6. Jambo said:

    "jim beam" <[email hidden]> wrote in message
    news:[email hidden]...

    Quoted message said:

    you must be mistaken - r.b.t "engineers" say steel never fatigues!

    [censored] again.

    Quoted message said:

    seriously though, re-welding the crack is never more than a temporary
    fix - you can never clean the metal interface sufficiently to get a bond
    that removes the stress riser.

    Spoken like a true poseur - welders usually clean the parts before
    re-welding them. Ever been in a workshop? Thought not.

    er, the bb is cracked, not cracked apart. you cannot clean inside a
    crack unless you open it up. that means the stress riser remains.

    Quoted message said:


    Quoted message said:

    the only viable repair is shell replacement, and frankly, economics of
    that are questionable if you take a decent repaint into account.

    [censored].

    do some math mr. modulus. a good paint job will cost you $500 or more.
    excluding the bb replacement. if you want to spend that much
    repairing a $300 frame, that's your business but it makes no financial
    sense.

    Quoted message said:


    Quoted message said:

    sentimental attachment aside, just look at a replacement frame. my
    bianchi pista is dead straight, rides great, and it's dead cheap. you can
    pick them up on craigslist even cheaper.

  7. Jambo' [email protected] said:

    "jim beam" <[email hidden]> wrote in message

    news:[email hidden]...

    Quoted message said:

    you must be mistaken - r.b.t "engineers" say steel never fatigues!

    [censored] again.

    Quoted message said:

    seriously though, re-welding the crack is never more than a temporary
    fix - you can never clean the metal interface sufficiently to get a bond
    that removes the stress riser.

    Spoken like a true poseur - welders usually clean the parts before
    re-welding them. Ever been in a workshop? Thought not.

    Quoted message said:

    the only viable repair is shell replacement, and frankly, economics of
    that are questionable if you take a decent repaint into account.

    [censored].

    Quoted message said:

    sentimental attachment aside, just look at a replacement frame. my
    bianchi pista is dead straight, rides great, and it's dead cheap. you can
    pick them up on craigslist even cheaper.

    Great. Perfect and appropriate impression of jim - six spokes short -
    beam.

    --

    Spike

  8. Scott Gordo said:


    I've discovered a massive crack in the bottom bracket lug of my
    Reynolds 531 1975 Paramount track frame that runs along the entire
    circumference at the base of the lug's seat tube opening.


    ....

    Quoted message said:

    Fixable? Recommendations? Welding in place would be cheap and I know a
    guy but it sounds too hot, I don't know any brazers, maybe I need a
    new lug installed? I'm not concerned about paint or anything, as this
    isn't a show bike and it has already been crappily repainted. I just
    don't want to *sniff* give her up.

    If it were my bike, I'd try using 45% silver to add a fillet joint
    over the cracked area. It would look funny on an otherwise lugged
    bike, but that should fix it without running the lug filler everywhere
    (if sensitively executed).

    Chalo

  9. jim beam said:


    er, the bb is cracked, not cracked apart. you cannot clean inside a
    crack unless you open it up. that means the stress riser remains.

    A fine bur on a Dremel tool makes quick work of prepping a crack for
    repair by brazing.

    Chalo

  10. Quoted message said:
    jim beam said:

    er, the bb is cracked, not cracked apart. you cannot clean inside a
    crack unless you open it up. that means the stress riser remains.

    Chalo said:

    A fine bur on a Dremel tool makes quick work of prepping a crack for
    repair by brazing.

    Yes and an acid wash is helpful too
    --
    Andrew Muzi
    www.yellowjersey.org
    Open every day since 1 April, 1971

  11. Scott Gordo said:

    I've discovered a massive crack in the bottom bracket lug of my
    Reynolds 531 1975 Paramount track frame that runs along the entire
    circumference at the base of the lug's seat tube opening.

    To clarify, the crack is in the lug, not the seat tube, The lugs are
    Nervex, but I think I remember reading that they used a different bb
    lug, The crack runs along the bb shell, around the back, back across
    the bb shell, and traces its way over the top of the down tube opening
    to meet at the other side.

    What a freakin' bummer!

    Fixable? Recommendations? Welding in place would be cheap and I know a
    guy but it sounds too hot, I don't know any brazers, maybe I need a
    new lug installed? I'm not concerned about paint or anything, as this
    isn't a show bike and it has already been crappily repainted. I just
    don't want to *sniff* give her up.

    Fixable, but not cheap. I fixed an old Atala "Record" frame that had
    failed in this manner, and I'm still riding it more than 20 years later.
    But you do need to know what you're doing WRT removing the old shell,
    brazing in a new one, keeping it all properly aligned, and (unless
    you're not too picky) a new paint job.

    How much do you like this bike? I got the Atala for free -- the frame
    was tossed by the previous owner -- and I was able to do all the labor
    myself. When I needed a new commuter bike after some low-life stole
    mine, I pulled the broken Atala out of storage and fixed it up. Been
    riding it ever since.

    --

    John ([email hidden])

  12. Jambo [email protected] said:

    "jim beam" <[email hidden]> wrote in message
    news:[email hidden]...

    Quoted message said:


    seriously though, re-welding the crack is never more than a temporary
    fix - you can never clean the metal interface sufficiently to get a bond
    that removes the stress riser.

    Quoted message said:

    Spoken like a true poseur - welders usually clean the parts before
    re-welding them. Ever been in a workshop? Thought not.

    A 1975 Paramount would have been silver brazed, not welded. The shell
    was probably a Nervex Pro stamped shell that failed at the base of the
    tube socket. Welding a bead around the crack large enough to be
    structurally sound would probably burn all the silver out of the
    shell/tube joint, leaving you with a very weak joint (but a strong
    shell, for what that's worth).

    I fixed my brass brazed Atala which had failed in the same manner by
    cutting the old shell into several pieces, carefully sweating the pieces
    off the tubes (4 joints involved: ST/BB, DT/BB and 2 CS/BB joints),
    fitting a new shell (investment cast, this time), which required
    removing the chainstay bridge since the chainstay sockets were slightly
    wider spaced than the original shell, getting it all aligned properly,
    brazing it up, and repainting. Altogether a non-trivial task, but still
    working fine after 20 years.

    --

    John ([email hidden])

  13. j

    Quoted message said:
    Quoted message said:

    [censored].

    do some math mr. modulus. a good paint job will cost you $500 or more.
    excluding the bb replacement. if you want to spend that much repairing
    a $300 frame, that's your business but it makes no financial sense.


    --------------
    When I use to take bikes like that to
    the LBS, they would say that they could
    put it in the dumpster for me. Now I
    just put them in the dumpster myself.

  14. Chalo said:
    jim beam said:

    er, the bb is cracked, not cracked apart. you cannot clean inside a
    crack unless you open it up. that means the stress riser remains.

    A fine bur on a Dremel tool makes quick work of prepping a crack for
    repair by brazing.


    well, you can cut the crack out and refill the hole i suppose, but it
    wouldn't be as strong. and seriously, it would take extraordinary luck
    and inordinate messing about with a crack without opening or removing it
    to clean it sufficiently to guarantee a good properly wetted join down
    into the crack itself. without that, you're just lipsticking the pig
    and the stress riser remains.

  15. A Muzi said:
    Quoted message said:
    jim beam said:

    er, the bb is cracked, not cracked apart. you cannot clean inside a
    crack unless you open it up. that means the stress riser remains.

    Chalo said:

    A fine bur on a Dremel tool makes quick work of prepping a crack for
    repair by brazing.

    Yes and an acid wash is helpful too

    I saw a bike on ebay a few weeks ago that had this exact problem. It had
    been welded. The weld was very strong, but the bracket was not. It had
    cracked again right next to the bead. I passed since I really didn't
    need a new project, particularly one of dubious outcome.

  16. a farmer might find a suitable tube, cut in half, cut top in half, cut
    snd file hole/slots for top half's tube bracing, file/grind/hammer
    tube to fit BB, clamp, tig tube, tig tube end to BB ends.

  17. datakoll said:

    a farmer might find a suitable tube, cut in half, cut top in half, cut
    snd file hole/slots for top half's tube bracing, file/grind/hammer
    tube to fit BB, clamp, tig tube, tig tube end to BB ends.

    Yes, he might. Farmers are famous for making worn-out pieces of [censored]
    last another year or two.

  18. Quoted message said:
    Quoted message said:
    Quoted message said:

    jim beam wrote:
    > er, the bb is cracked, not cracked apart. you cannot clean inside a
    > crack unless you open it up. that means the stress riser remains.

    Quoted message said:
    Quoted message said:
    Chalo said:

    A fine bur on a Dremel tool makes quick work of prepping a crack for
    repair by brazing.

    Quoted message said:
    A Muzi said:

    Yes and an acid wash is helpful too

    vey said:

    I saw a bike on ebay a few weeks ago that had this exact problem. It had
    been welded. The weld was very strong, but the bracket was not. It had
    cracked again right next to the bead. I passed since I really didn't
    need a new project, particularly one of dubious outcome.

    Welding over a silver braze, or any braze for that matter, is a Welding
    99 error - predictable failure.
    To this specific bike: If it is cracked all around, he may be able to
    get reasonable alignment which will eliminate the stress on the joint
    which caused the crack. If so, as Chalo notes, a cleaned simple butt
    joint silver brazed with full penetration should be adequate. Regarding
    that type of crack see also:
    http://www.yellowjersey.org/zito.html
    --
    Andrew Muzi
    www.yellowjersey.org
    Open every day since 1 April, 1971

  19. in rec.bicycles.tech A Muzi said:

    Welding over a silver braze, or any braze for that matter, is a Welding
    99 error - predictable failure.
    To this specific bike: If it is cracked all around, he may be able to
    get reasonable alignment which will eliminate the stress on the joint
    which caused the crack. If so, as Chalo notes, a cleaned simple butt
    joint silver brazed with full penetration should be adequate. Regarding
    that type of crack see also:
    http://www.yellowjersey.org/zito.html

    Yeah, I'd have to see it; however, I'd give odds that the frame is
    dead. I once tried to repair a BB shell and it was an unmitigated
    disaster. The guy had forced the cups into the wrong sides and musta
    used a big cheater. I tried to build it up with a tig outfit and
    rebore it... one of those ideas that should have worked, but didn't.
    I was trying to do a favor for a friend and he ended up threatening to
    sue me for a new frame.

    Although, what that has to do with the current case, I haven't a clue.

    Jones

  20. !Jones said:


    Yeah, I'd have to see it

    Wise move.

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